I don't see why that's relevant - you can just get a different screen if you need those aids. Otherwise...just use the rear screen, it's not that big of a deal.

I'm also able to consistently obtain accurate manual focus using my D600's factory focusing screen with a 50/1.4 lens, even though there's no split screen, microprism, or coarse grain optimized for fast lenses.

the exposure may not be correct, it cannot have the variety of overlay information supplied by an EVF, it doesn't allow for the variety of MF aids that are available.

Exposure preview is absent, but that also prevents exposure preview from getting in the way. For example, if you're shooting a high contrast scene and the camera meters incorrectly, you might have a really hard time seeing your subject through an EVF.

Correct, but then you know to adjust or to switch to spot...

But then you waste the half second that you have to get the shot. There are many situations in which a not-so-perfectly exposed shot of the right moment is far preferable to a well exposed shot that misses the right moment.

With an OVF, you can be aware (with experience) that the camera isn't going to auto expose properly, and shoot anyways with full view of the subject and just fix the exposure in raw conversion later. Again, you get the shot, and fix things later (vs fixing things right there and losing the opportunity).

With respect, until they offer LV in the VF, it isn't offered now.

Why does it have to be in the VF?

I'd rather keep it on the rear screen. Sacrificing the action-capturing and battery saving potential of the OVF to get two views of the same thing in different parts of the camera isn't worth it.

Did I also mention battery drain? Keeping the sensor and image processing pipeline on just to get a preview doesn't come free.

I don't think EVF cameras at the moment are ready for prime time. Maybe they'll be just as good in 10 years, but that isn't a good reason to buy one (better to just wait until they're there).